1. Field of the Invention
The present invention relates to a light-emitting control circuit, and more particularly to a light-emitting control circuit applied in a wrist training ball.
2. Related Art
A wrist training ball (as disclosed in U.S. Pat. No. 4,150,580) utilizes a gyroscopic principle and a strong force generated during rotation under the eccentric force and inertial effects, so that a trainer holds and rotates a ball body with a hand to exercise an arm and a wrist. The wrist training ball is widely applied in wrist strength exercises, especially exercises about holding strength of fingers, endurance of wrists, and muscle strength of forearms, biceps, triceps, ligaments, and shoulders.
In order to make the use of the wrist training ball become more interesting, light-emitting diodes (LEDs) for emitting light rays can be disposed on the wrist training ball. Coils and a magnet are disposed on the wrist training ball, and a magnetic field of the magnet is changed due to the rotation of the wrist training ball, such that the coils generate electric power, so as to supply the power to the LEDs for emitting light. Additionally, in order to produce various light emission effects, a programmable controller or a microprocessor is connected to a plurality of LEDs having different colors in a method of the prior art. Specific programs are written in the controller, and the LEDs are controlled to be turned on and off intermittently driven by logic programs, so as to produce various light emission effects (as disclosed in U.S. Pat. No. 7,101,315).
However, a plurality of LEDs and controllers are all loading for the circuit. The larger the loading is, the greater the resistance will be, thereby causing a lower brightness of the LED. In addition, the controller itself requires a great deal of electric power for operation. That is to say, most of the electric power generated by the induction coils is supplied to the controller, thereby resulting in the even lower brightness of the light rays emitted by the LED, so that the light ray effects become rather poor.
In addition, the programmable controller or the microprocessor has a higher cost than a common passive device. For example, the use of the programmable controller or the microprocessor greatly increases the manufacturing cost of the wrist training ball.
Therefore, in order to provide the wrist training ball with various light emission and flickering effects, the programmable controller or the microprocessor is adopted, which sacrifices the light emission intensity of the LEDs or increases the cost of the wrist training ball.